Answer:
10
Step-by-step explanation:
Let XY = a
Since,
XY + YZ = XZ
a + YZ = 24
YZ = 24 - a
By angle bisector property:
[tex]\frac{WX}{WZ} = \frac{XY}{YZ} \\ \\ \frac{15}{21} = \frac{a}{24 - a} \\ \\ \frac{5}{7} = \frac{a}{24 - a} \\ \\ 5(24 - a) = 7a \\ \\ 120 - 5a = 7a \\ \\ 120 = 7a + 5a \\ \\ 120 = 12a \\ \\ a = \frac{120}{12} \\ \\ a = 10 \\ \\ \implies \: XY = 10[/tex]
